Question: Khan.scratchpad.disable(); To move up to the maestro level in his piano school, Michael needs to master at least $173$ songs. Michael has already mastered $11$ songs. If Michael can master $10$ songs per month, what is the minimum number of months it will take him to move to the maestro level?
Answer: To solve this, let's set up an expression to show how many songs Michael will have mastered after each month. Number of songs mastered $=$ $ $ Months at school $\times$ Songs mastered per month $+$ Songs already mastered Since Michael Needs to have at least $173$ songs mastered to move to maestro level, we can set up an inequality to find the number of months needed. Number of songs mastered $\geq 173$ Months at school $\times$ Songs mastered per month $ +$ Songs already mastered $\geq 173$ We are solving for the months spent at school, so let the number of months be represented by the variable $x$ We can now plug in: $x \cdot 10 + 11 \geq 173$ $ x \cdot 10 \geq 173 - 11 $ $ x \cdot 10 \geq 162 $ $x \geq \dfrac{162}{10} \approx 16.20$ Since we only care about whole months that Michael has spent working, we round $16.20$ up to $17$ Michael must work for at least 17 months.